Running Apple is a lonely job, according to CEO Tim Cook. It's hard work, with long hours, and you have to make decisions that affect tens of thousands of employees.

But he has a few people he can turn to for advice, Cook revealed in a lengthy interview with the Washington Post. Those people happen to be former President Bill Clinton, Goldman Sachs CEO Lloyd Blankfein, and investing legend Warren Buffett.

That's because they understand what Cook is going through, whether it's testifying before Congress or figuring out how big a dividend Apple should issue.

"When I was going through [the question of] what should we do on returning cash to shareholders, I thought who could really give us great advice here? Who wouldn't have a bias? So I called up Warren Buffett. I thought he's the natural person, and so I try to go through that process on everyone. That doesn't mean I always do what they say. But I think it's incumbent on a CEO to not just listen to points of view but to actually solicit them. Because I think, if not, you quickly become insular. And you're sort of living in the echo chamber."

He continued:

"For the hearing [about Apple's tax practices in 2013], I've never testified in front of Congress before. So I called up [Goldman Sachs CEO] Lloyd Blankfein, because I looked back to say who's done this before? I knew Lloyd and thought he'd be honest with me. I called up President Clinton. He knows a lot about the politics. I'd not met him through a political connection. I'd met him through the foundation. I went to Laurene, Steve's wife. Laurene has the lens of knowing me and deeply understanding Apple."

Cook isn't the only tech mogul to have Buffett's ear. Microsoft founder Bill Gates and Buffett have a famous friendship going back 25 years that not only includes philanthropic joint ventures but also sleepovers and cookies for breakfast.